Hydraulically actuated planetary gearing for sawmill feed works



Oct. 19, 1954 G. D. FERGUSON HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS 8 Sheets-Sheet l Filed Aug. 22, 1951 KNW Oct. 19, 1954 G. D. FERGUSON 2,691,994 HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS Filed Aug. 22, 1951 a sheets-sheet 2 ,47m/eser.:

Oct. 19, 1954 G, D. FERGUSON 2,691,994

HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL. FEED WORKS Filed Aug. 22, 1951 8 Sheets-Sheet 5 Snowdon 10X 9 /enn Fguson @Ho-:ump

Oct. 19, 1954 G. D. FERGUsoN 2,691,994

` HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS Filed Aug. 22, 1951 8 Sheets-Sheet 4 vanto@ Oct. 19, 1954 G. D. FERGUSON HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILI.. FEED WORKS 8 Sheets-Sheet 5 Filed Aug. 22, 1951 Oct. 19, 1954 G. D. FERGUSON 2,691,994

HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS Filed Aug. 22, 1951 8 Sheets-Sheet 6 Oct. 19, 1954 G. D. FERGUSON HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS 8 Sheets-Sheet 7 Filed Aug. 22, 195].

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INVENToR. lem Ear Zwan Oct. 19, 1954 Filed Aug. 22, 1951 G. D. FERGUSON HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS 8 Sheets-Sheet 8 Patented Oct. 19, 1954 HYDRAULICALLY ACTUATED PLANETARY GEARING FOR SAWMILL FEED WORKS Glenn D. Ferguson, Onaga, Kans.

Application August 22, 1951, Serial N 0. 243,145

3 Claims.

(Granted under Title 35, U. S. Code (1952),

sec. 266) This invention relates to the control of mechanical movements and more particularly to the power train control for a reciprocating carriage of the type especially adapted for use with a sawmill.

In a sawmill it is customary to provide a carriage for supporting a log movable in one direction to feed the log to the saw and in the reverse direction to return to its starting place. It is preferable that the return motion be accomplished more quickly than the feed, the latter being restricted by the speed with which sawing may be accomplished, in order to reduce the time required for a sawing cycle.

Heretofore this has been accomplished by various systems, all rather complex or suffering from various deficiencies, by such means as employing a plurality of friction belt drives including shifting means therefor, or through intricate pulley systems and the like. Inherently accompanying these systems are substantially frictional losses, large numbers of parts such as ropes, belts and the like which involve substantial bulk and weight and require frequent replacement.

Accordingly, it is an object of the present invention to provide a power train and control means therefor particularly applicable but not restricted to a sawmill feed works in which the inherent friction accompanying the operation thereof, and the bulk and weight of the mechanism, are reduced to a minimum.

A further object is the provision of a sawmill feed works which is simple to construct from a minimum of parts and has a relatively small bulk and weight.

A still further object is the provision of a sawmill feed works which is so constructed as to reduce friction occasioned by its operation to a minimum and which is easy to operate and maintain.

A further object is the provision of a reversing and speed-changing mechanism particularly adapted for use with a sawmill feed works which is self-lubricating and sealed against the entry of foreign matter.

A still further object is the provision of a sawmill feed works which operates through an erlicient planetary gear system and which is of a light weight and easy to operate.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a perspective illustrating one embodiment of the invention;

Fig. 2 is a partial section throughl the gear mechanism and housing therefor;

Fig. 3 is an enlargement in section of the lefthand portion of the gear and brake-clutch mechanism of Fig. 2;

Fig. 41s an enlargement in section of the righthand portion of the gear and brake-clutch mechanism of Fig. 2;

Fig. 5 is a section on the line 5-5 of Fig. 2;

Fig. 6 is a side elevation of a planetary gear hanger;

Fig. 7 is a section on the line 'I-l of Fig. 6;

Fig. 8 is a section on the line 8 8 of Fig. 6;

Fig. 9 is an enlargement in section illustrating the left-hand master cylinder assembly shown in Fig. 2;

Fig. 10 is an enlargement in section illustrating the right-hand master cylinder assembly of Fig. 2;

Fig. 11 is a perspective from the opposite side of the saw of Fig. 1 illustrating a modified form of the invention;

Fig. 12 is a plan view partly in section of the drive cylinder employed with the embodiment of Fig. 11; and

Fig. 13 is an enlarged fragmentary vertical section of a resilient valve cup member and associated parts shown in Figs. 9 and 10.

Referring to the drawings and particularly to Figs. l and 11, a sawmill is shown including a track ID having left and right rails II and I2 (Fig. 1) spaced apart by and supported on a plurality of cross-members I3. Movably mounted on the track I0 is a carriage I4 having crossmembers I5 for supporting a log to be sawed and means (not shown) for holding a log on the carriage.

Positioned adjacent the track is a supporting frame I6 having end members Il, I'I and side members I8. Rotatably supported across the side members I8 is a mandrel shaft 2l] having a drive pulley 22 at one end and a circular saw 24 at the other. The pulley 22 is adapted to be driven by a belt 25 receiving its power from a conventional source (not shown) such as a smaller pulley driven by a gasoline or other type engine.

On the mandrel shaft 20 intermediate the pulley and saw is a sprocket 2B having engaged therewith a chain 2l which drives a smaller idler sprocket 23 mounted by a bracket 30 on the end frame member Il.

Spaced from and substantially parallel with the mandrel shaft 2i] is a main shaft 32 having a sprocket 34 disposed so as to be driven by chain 2I as it travels over sprockets 26 and 28. Shaft 32 is rotatably connected to a drive shaft 36 through a universal joint 38 (Fig. 1l). Drive shaft 36 carries a substantially cylindrical housing 39 and is journalled in left and right bearing hangers 40 and. 4|- rigidly connected to the left and rightrails and I2.

Wound around the periphery of the housing 39 is a cable 42, 42' which extends through a sheave (not shown) mounted beyond carriage I4 and adjacent the track at one end and through a second sheave (not shown) mounted adjacent the track at the other end, the carriage being connected to the length 42 thereof. By rotating the housing or drum 39 in one direction the carriage |4 Will be drawn toward the saw 24 to feed the log thereto and by reversing rotation of the housing 39 the carriage may be returned to its original position.

In order to rotate the housing 39 in the desired directionv at will and to provide a more rapid return speed of the carriage: than the feed speed, a planetary gear system and braking-clutching mechanism is mounted Within the housing 39'.

Referring particularly to Figs. 2 through 1.0, d-rive shaft 36 is provided with a' sun gear 44, the latter being keyed to shaft 36- and located sub-Y stantially centrally of housing 39. Rotatably mounted adjacent the sun gear 44 by left and right roller bearings 46 and 41 are left and right hangers 48 and 49, the hangers being connected by'suitable fasteners extending through spaced apertures 50. Stub shafts 52 extend through spaced apertures 53 and have mounted thereon bearingsv 54. Each of the hangers has a plurality of spaced inclined oil holes 55 permitting circulation of.' oilr from the bearings 46 and 41 into the space between the left and right hangers. Be" tween ha-ngers 48 and 49 and mounted on the bearings, 54 are a plurality of planetary gears 56, three being shown spaced at equal intervals about the axis of the shaft 36. Planetary gears 96 are, therefore, rotatablyl mounted relative to the comlected hangers 48 and 49, the hangersy being rotatably mounted on the shaft 36.

An internal ring gear 60 surrounds and engages the planetary gears 56 and is rigidly secured to the right portion 6| of the interior Wall of the housing 39. The housing 39', as previously stated, is substantially cylindrical, and has left and right open ends 62 and 63 and an internal flange |55 with a bearing receiving surface 66 disposed between itsv ends. The hangers 48 and 49 have circular Wheel portions 68 to which the fasteners and planetary gears are connected, and hub portions 69, 69' extending outwardly from the connected portions of the hangers, the hub portions. being carried on the shaft 3.6 by the bearings 46 and. 411.

Encircling each of the hubs' 69, 69 of the left and right hangers, respectively, is a ball-bearing assembly comprising an inner race 10, a plurality of balls 1|, and an outer race 12. Mounted on the outer race 12 of the bearing 46 surrounding the hub of the left hanger 48 is the bearing 4 the end plate and the hub 69 of the right-hand hanger 49.

An internal iiange is provided in the bore of the hub 69 and engages the bearing 41 on one side, they other side. of, the bearing being spaced from the sun gearA 44 by a. spacer 8|, the axial position of the sun gear being maintained by rings 82 positioned in grooves around the shaft at either side of the sun gear. On the other side ofthe flange 80' and between the hub 69 and the shaft 3.6 is a ring of packing material 83.

Adjacent the end of the hub 69 is a carriage plate 85 which is attached to the ange 86 of a thrust hearing 81 by fasteners 88 extending through the flange 86, the carriage plate 85 and into the hub of the right-hand hanger 69'.

Connected to the carriage plate 85 by fasteners 89 is a right-hand brake drum 90. A backing plate 92 is rigidly mounted on the right-hand bearing hanger 49| by suitable fasteners 93 and has mounted on. it brake shoes 94 having a hydraulic wheel cylinder 95 and a retracting spring 96, a fluid line 91 leading from the cylinder 95 to a fitting 98 connected to a master cylinder assembly |00, the mastercylinder assembly being; mounted on the right bearing hanger 4|.

Referring again to the interior of the housing 39, a left-hand end plate |02 (Fig. 3) is connected to the flange 65 of the housing by fasteners |03, and has a flange |94 engaging the external side of the outer race 12 of the roller bearing assembly mounted on the hub 69, the central` portion of the end plate |02. having a bore |05 to receive the shaft 36, packing |06 being provided tov seal the bore.

Rigidly mounted on the interior of the left-- hand end 62 of the housing 39 is a clutch drum'A |06. Keyed on the portion of the shaft surrounded. by the clutch drum |08 is a hub |I8 having a flange- ||I which is connected by fasteners ||2 to. a left-hand backing plate |I4. It is appare ent, therefore, that the backing plate I|-4 rotates with the shaft 36 and that the clutch drum |08 is affixed to the housing 3-9. A clutch shoe I|6v mounted on the backing plate ||4 may be actuated by a Wheel cylinder I I8 and suitable linkage including a. retracting spring (notv shown).

Each of the Wheel` cylinders 95 and H9 is of conventional design and includes a tting |20 for connecting the fluid line thereto, and a bleeder valve |22.. The cylinder ||8 of the left clutch shoe is connected by line |24 to a fitting |25 on the shaft 36. The shaft 36 has a bore |21 extending to a countersunk recess |28 at the end of the shaft, the exterior of the end. of the shaft being threaded at |29 to engage a master cylinder assembly 30. (See Fig. 9.) A

The shaft 36 is carried in the left bearing hanger 40 by a bearing |3I, the bearing hanger having an enlarged bore |32 at its other end for receiving the master cylinder assembly |30. At

. its base the bearing hanger 40 has flanges |33 engaged by fasteners |34 which secure it to a frame member |35 attached to the trackv Il.

The master cylinder |00 (Fig. l0) of the right brake drum assembly has a plug |36 engaged With the interior threads |29 of the master cylinder |80, the plug having a bore |31 and countersunk recess |31 connecting the interior of the master cylinder with the fluid line 91 by means of the fitting 98. Each of the master cylinders |80 and |30 is of a substantially cylindrical configuration and has a. central bore |40. At the rear of the central bore |40 is a flange |4I and a portion |42 of slightly less diameter than the bore |40. Positioned in the bore |45 is a piston |44 having a body of spool-like conguration with rims |45 at either end, a washer |46 being provided between the rims and adjacent the rear rim. In front oi the piston is a resilient cup member |48 having a compression spring ||9 engaged therewith resiliently spacing it and the piston away from a resilient washer or grommet |50. The master cylinder |30 has its grommet |50 seated in the counter-sunk recess |23 of the shaft 36, and the master cylinder has its grommet |55 positioned in the countersunk recess |37 of the plug |36. Positioned over the bore of the grommet |50 is a resilient valve cup member |5| having a rigid cup member |52 of similar' configuration engaged therewith, the member |52 being provided with a plurality of spaced apertures |53 on its sides.

At its other end the piston IM has a recess |545 for receiving a push rod |55. The push rod |55 associated with the master cylinder |35 has a lever I mounted on a post |6| of the frame member |35 for actuation thereof. Similarly the push rod |55 of the master cylinder |00 has a lever |52 mounted on a pivot |63. At the other end of the levers |55 and |52, attached yokes |6|l and |55 are connected by a tie rod |66 (Fig. 2). Also connected to the yoke |65 is a rod |58 (Fig. l) which is adapted to be reciprocated through suitable linkage |69 actuated through a lever |70 pivotally attached to the end frame ii" by a bracket l'll.

In the operation of the sawmill the saw 21| is rotated at substantially constant speed through the shaft 25, logs being fed to the saw by the reciprocable carriage lil, the carriage being returned to its previous position a'fter the sawing operation for receiving another ylog and moving it into engagement with the saw at the desired rate of feed.

As the shaft 2|! rotates, the shaft 32 to which the drive shaft t6 is coupled is driven in the opposite direction through the sprocket 25, chain 2 and the sprocket 3Q. Hence, under normal operating conditions, both the shafts 2t and 32 continuously rotate at constant speed.

With both the lefthand clutch and right-hand brake shoes I6 and 96| disengaged rotation of the sun gear merely causes the planetary gears to run around the internal gear 5|), carrying with them the left and right hangers it and 49, the hangers being rotatably engaged with both the housing 35 and the shaft 35; hence, with the two shoes disengaged, rotation of the drive shaft does not rotate the housing 39.

In order to drive the housing S9 directly, the left clutch shoe llt is engaged with the clutch drum |08, thus providing a direct connection from the shaft 35 through the collar i It, backing plate iid, the shoe H6 and drum Hit to the housing 39. Under these conditions the entire housing is driven directly trom the shaft tti, and rotates in the same direction and at the saine angular velocity as the shaft. Referring to Fig. l, rotation of the shaft t2 in the direction of the arrow will result in winding the cable i? onto the right half of the housing 39, thus re traeting the carriage lf2 from the saw, the cable 52 having an end attached to the carriage and passing around a sheave beyond the carriage. This portion of the operation is commonly referred to as the gigback.

To feed the carriage toward the saw and at a slower rate of speed the rotation of the drum must be reversed, and the angular velocity of the drum 39 reduced to less than that of the shaft 35. To achieve this condition clutch shoe ||6 is released and brake shoe 95 mounted on the stationary backing plate 92 is engaged with brake drum 9d. As the brake drum 9G is connected to the hangers 48 and 49, braking of the drum 9|) similarly restricts rotation of the hangers and the planetary gear carried thereby. lAs previously pointed out, with both the left-hand clutch and right brake shoes disengaged, the planetary gears merely run around the internal gear Se carrying the connected left and righthand hangers with them. Accordingly, any restriction of rotation of the hangers results in torque being exerted on the internal gear 60. Thus, the right-hand brake shoe may be lightly engaged with its brake drum, in the manner of the gradual engagement of a clutch, to produce a light torque on the housing. Referring to Fig. 5, it is apparent th'at counter-clockwise movement of shaft 35 will produce clockwise movement of the planetary gears 56, and assuming that the connected hangers are restricted from movement by the engagement of the righthand brake shoe with its drum, clockwise motion of the ring gear and the connected housing are produced. Hence, with the right brake assembly engaged, rotation of the housing is reversed.

Because of the larger movement of teeth in the internal gear 5G than in the sun gear 44, the angular velocity of the internal gear and housing are less than that of the sun gear. Itis, of course, within the scope of the invention to vary the ratio between the gears to produce the difference in angular velocity desired. I have Afound that a ratio of l to 2.5, approximately, is particularly satisfactory for a device of the approximate proportions shown.

In order to actuate the brake and clutch the double-acting lever may be oscillated to operate the left and right master cylinders. Actuation of the linkage 68, til to move a push rod 55 inwardly forces hydraulic iiuid within the master cylinder through the apertures 53 of the cup |52 thus iieXing the sides of the resilient cup |5| inwardly and permitting the fluid to flow into the bore 2'! (or |31) through the fluid line to the respective brake or clutch cylinder. Retraction of the lever permits the spring |49 to move the piston |154 backward, fluid being drawn back through the fluid line and the bores to the master cylinder as the valve member |5| and cup |52 are lifted oi the grommet seat |55 until the pressure is equalized.

'I'he modification shown in Figs. 1l and 12 employs the same housing 39 and gear and brakeclutch mechanism previously described except for the master cylinder arrangement. Figs. 11 and i2, it is understood, are viewed from the opposite side ofthe structure from that shown in the preceding gures. In the modification, the brake drum has the fluid line 9'! extending through suitable coupling means 5t to a master cylinder |6| adapted to be actuated by the push rod |62 attached by yoke |63 to a lever |54', the lever being pivoted about the rod |55. At the other end the shaft 35 is more elongated than that described in the preceding figures and is journalled in a bearing hanger Iii by a bearing The iiuid line |24 from the cylinder l |8 is attached to the shaft 35 by the tting |25, the shaft 36 havacercar ing. a bore |21 communicating with the enlarged bore |40' at the end of the shaft.

Disposed within the enlarged portion |40 of the bore is a conduit |12 surrounded by a packing |13 and having an enlarged head |14 fitting snugly Within the bore |4. A nut |11 is threadedly engaged with the end |18 of the shaft 36 and has a bore |11 aligned with bore |40. Extending into the bores is a plug having a flanged portion |15, the flanged portion having a plurality of apertures |16 receiving bolts |80 threaded into the head of the nut |11. Compression springs |8| on the shafts of the bolts and abutting the bolt heads and nut |11 permit adjustment of the plug |15 against the packing |13.

TheA conduit |12 is connected to a master cylinder |83 through suitable connecting members and a fluid line |84 as shown. The master cylinder |83 has a push rod |85 connected by the yoke |86 on the side of the pivot |66 opposite to the push y rod isz'.

In the operation ofthe modified form of the device, oscillation of the lever to a forward or reverse position to actuate the respective master cylinders actuates the brake or clutch mechanism to produce movement similarly to that described above in connection with Figs. 1 to 10.

Although the device has been described as including a hydraulic brake-clutch system the invention also contemplates the use of brake-clutch systems of other types, such as an electric brakeclutchmechanism.

Due to the particular construction and arrangement of the parts, the device is easy to operate, requiring merely the movement of a lever in one direction to effect a change in both speed and direction of rotation of the drum on which the cable is wound and hence the speed and direction of movement of the sawmill carriage. The gear and brake-clutch mechanism is largely self-contained and is sealed from the entry of foreign substance, thus simplifying installation, transportation and upkeep thereof. In addition, because of the elimination of a multiplicity of speed and direction changing means, such as pulleys, driving belts and the like, the bulk and weight of the mechanism is substantially reduced from that heretofore required. Itis, furthermore, apparent that the unitary gear and brake-clutch mechanism is adapted for use with conventional sawmill equipment and thaty the installation and application thereto is relatively simple.

It is apparent, therefore, that the invention includes a planetary gear mechanism having a pair of brake and clutch assemblies associated therewith, the clutch one of the assemblies being adapted to connect the drive shaft in direct drive relation with the drum on which the cable is wound in order to provide a substantially rapid gigback; disengagement of the aforesaid clutch assembly and engagement of the brake prevents rotation of the assembly carrying the planetary gears such that rotation of the sun gear produces a rotation thereof without planetary movement and hence reverses rotation and angular velocity of the cable drum through an internal gear attached thereto. A further feature of the invention is the arrangement of the hydraulic connections to the brake and clutch mechanisms, one line passing through a lportion of the rotating drive shaft and the other line being attached to a stationary brake shoe.

It will be apparent that the invention is not limited to the specific construction of the embo'diment shown, but includes reasonable variation therefrom and the substitution of reasonable 8 equiyalents,v and therefore the invention is only limited as'found in the appended claims..

Having thus described my invention, what. I claim as, new and Wish7 to secure by Letters Patent is:

1. Reciprocating. mechanism for reciprocating a mechanically actuated. carriage member for conveying articles to be worked to a working; device for operating on the articles, and control means for said reciprocating mechanism, said mechanism and' control means comprisingA a main shaft, a drive sprocket on the main shaft, an idler sprocket spaced from the drive sprocket, chain drive means engaging the drive sprocket and the idler sprocket and driving the. drive sprocket, a drivey shaft connected to said main shaft, a sun gear keyed on said drive shaft, left and right connected hangers rotatably mounted on said shaft, a plurality of planetary gears rotatably mounted between said hangers and carried thereby, said planetary gears being engaged with said sun gear, an internal ring gear engaged with said. planetary gears, a housing for said gears and rigidly connected' to said ring gear, said housing comprising a substantially cylindrical body open at the ends and having an internal bearing receiving flange, a cable wound around the housing and attached to the carriage, said hangers each having hub portions projecting from a side thereof, a bearing mounted on each of the hub portions, the bearing on the hub portion of the left hanger mounting the bearing receiving flange, a first plate-secured to the right end of the housing andr engaging the bearing on the right hanger, a second plate secured to the bearing receiving flange and engaging the bearing on the left hanger, a carriage plate connected to the right hanger, a right brake drum connected to said carriage plate, a right brake shoe adapted to engage said brake drum, a right backing plate for said brake drum and carrying said brake shoe, said backing plate being secured to the frame, a left clutch drum rigidly mounted on the left end of said housing, a hub rigidly mounted on said shaft adjacent the left clutch drum, a left backing plate rigidly mounted on said hub, a left clutch shoe mounted on said backing plate and adapted to engage said clutch drum, and actuating means for each of said shoes, said actuating means forv said shoes each comprising a hydraulic cylinder connected to said shoe, a master cylinder, and fluid passage means connecting said cylinder and said master cylinder, the left master cylinder being rigidly connected to an end of said drive shaft; a bearing hanger mounted on the frame, the end of said drive shaft being journalled in said bearing hanger, the uid passage means for said left master cylinder including a bore through a portion of said drive shaft and connected to tubing extending to the left clutch cylinder, and a bearing hanger for the portion of the drive shaft at the right side of the housing and rigidly attached to the frame, the right master cylinder being rigidly mounted on said bearing hanger; Veach of said master cylinders comprising a cylindrical body having a reservoir and a bore in communication therewith, a piston in the bore, a push rod for actuating the piston, a gasket cup engaged with said piston, a grommet having a resilient cup-shape valve engaged therewith and a metal cup engaged with the valve, the cup having spaced apertures on its side, a spring normally holding said valve apart' from said piston; and actuating means for said push rods, said means 9 including a lever pivotally mounted adjacent each push rod and adapted to engage the push rod, means connecting the levers, and means for actuating the levers simultaneously, one being depressed as the other is retracted.

2. Reciprocating mechanism for a mechanically actuated carriage member conveying Workpieces to a working device for operating on the workpieces and control means for the said reciprocating mechanism, said mechanism and control means comprising a drive shaft, a mandrel shaft adjacent to the drive shaft, means on said drive shaft engaged With and adapted to be driven by the mandrel shaft, a sun gear keyed on said drive shaft, means rotatably mounted on said shaft and carrying a plurality of rotatably mounted planetary gears, said planetary gears being engaged with said sun gear, an internal ring gear engaged with said planetary gears, a housing for said gears and rigidly con nected to said ring gear, means engaged With the housing operative to move the carriage, means rotatably mounting the housing on the means carrying the planetary gears, a right brake drum connected to the means carrying the planetary gears, a right brake shoe adapted to engage said brake drum, a right Ibacking plate for said brake drum and carrying said brake shoe, said backing plate being secured to the frame, a left clutch drum rigidly mounted on the left end of said housing, a hub rigidly mounted on said shaft adjacent the left clutch drum, a left backing plate rigidly mounted on said hub, a left clutch shoe mounted on said backing plate and adapted to engage said clutch drum, and actuating means for each of said shoes, said actuating means for said shoes each comprising a hydraulic cylinder connected to said shoe, a master cylinder, and a uid passage connecting said cylinder and said master cylinder, the left master cylinder being rigidly connected to an end of said drive shaft; a bearing hanger mounted on the frame, the end of said drive shaft being journalled in said bearing hanger, the fluid passage for said left master cylinder including a bore through a portion of said drive shaft and connected to tubing extending to the left clutch cylinder, and a bearing hanger for the portion of the drive shaft at the right side of the housing and rigidly attached to the frame, the right master cylinder being rigidly mounted on said bearing hanger; each of said master cylinders comprising a cylindrical body having a reservoir and a bore, a piston in the bore, a push rod for actuating the piston, a gasket cup engaged with said piston, a grommet having a resilient cup-shape valve engaged therewith and a metal cup engaged With the valve, the cup having spaced apertures on its side, a spring normally holding said valve apart from said piston; and actuating means for said push rods, said means including a lever pivotally mounted adjacent each push rod and adapted to engage the push rod, means connecting the levers, and means for actuating the levers simultaneously, one being depressed as the other is retracted.

3. In a saw mill including a frame supported mandrel shaft mounting a saw and a carriage movably mounted adjacent thereto, the improvements which include mechanism for reciprocating the carriage and control means for the said mechanism, said mechanism and control means comprising a drive shaft, means on said drive shaft engaged with and adapted to be driven by the mandrel shaft, a sun gear keyed on said drive shaft, means rotatably mounted on said shaft and carrying a plurality of rotatably mounted planetary gears, said planetary gears being engaged with said sun gear, an internal ring gear with said planetary gears, a housing for said gears and rigidly connected to said ring gear, said housing being adapted to engage means operative to move the carriage, the housing being rotatably mounted on the means carrying the planetary gears, a brake means connected to the means carrying the planetary gears, a first actuating means for said brake means and secured to the frame, a clutch means mounted on said housing, actuating means for said clutch means and mounted for rotation with said shaft, and means for operating each of said actuating means, said operating means comprising first and second master cylinders, and fluid passage means conu necting said actuating means and said master cylinders, the first master cylinder being rigidly connected to an end of said drive shaft adjacent' an end of said housing; a bearing hanger mounted on the frame, an end of said drive shaft being journalled in said bearing hanger, the fluid passage for said rst master cylinder including a bore through a portion of said drive shaft and connected to tubing extending to the iirst actuating means, and a bearing hanger for the portion of the drive shaft at the other end of the housing and rigidly attached to the frame, the second master cylinder being rigidly mounted on said bearing hanger; each of said master cylinders comprising a cylindrical body having a reservoir and a bore, a piston in the bore, a push rod for actuating the piston, a gasket cup engaged with said piston, a grommet having a resilient cup-shaped Valve engaged therewith and a metal cup engaged with the valve, the cup having spaced apertures on its side, a spring normally holding said valve apart from said piston; and actuating means for said push rods, said means including a lever pivotally mounted adjacent each push rod and adapted to engage the push rod, means connecting the levers, and means for actuating the levers simultaneously, one being depressed as the other is retracted.

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